Reduces the effect of EMP on robot power cells

Temporary fix to resolve #8454

code/modules/mob/living/silicon/robot/robot.dm

@@ -50,6 +50,8 @@ var/list/robot_verbs_default = list(
 	var/obj/item/weapon/cell/cell = null
 	var/obj/machinery/camera/camera = null
 
+	var/cell_emp_mult = 2
+
 	// Components are basically robot organs.
 	var/list/components = list()